This invention relates to a composition for treating a textile substrate to impart softening, smoothness, and soil-release characteristics thereto, which composition can be spray-dispersed onto the textile to be treated.
The washing agents commonly applied in laundering consist of soap and/or the synthetic detergents, such as long-chain alkyl sulfates or sulfonates and fatty alcohol condensation products which are usually mixed with builder salts, such as alkali carbonates, silicates, and/or phosphates. These builder salts have a tendency, however, to react with the calcium and magnesium ions present in the ordinary washing water, whereby salts are precipitated which are liable to be deposited onto the fibers of the textile during the washing step, especially if detergents are used that are not capable of keeping the soil and other undissolved substances sufficiently suspended in the washing solution. The mineral salts deposited onto the fibers render the fabrics liable to be weakened, particularly at those parts of the textile goods which are exposed to friction or rubbing, as, for instance, the edges of collars or sleeves. In addition, the deposited mineral salts give the laundered textiles a poor, boardy feel, particularly at those areas of the fabric which are exposed to friction and creasing, such as collars and cuffs. This poor hand of laundered fabrics and resulting discomfort during use have in part resulted in the creation of a large and expanding market for softener formulations capable of improving the softness or "hand" of laundered textiles. It has been found that the treatment of such materials with softening agents improves their softness of feel and may prolong the useful life of the textile materials. Softeners also facilitate ironing by lubricating the fibers so that wrinkling is reduced and friction between fibers and the iron is reduced. Additionally, it has been found that treatment of fabrics with softeners generally results in a fabric having a reduced tendency to accumulate electrical charges which create undesirable static cling.
The genesis of synthetically produced textile fibers has brought about a tremendous effort in the textile industry along numerous avenues. There has been much research effort directed to the improvement of these synthetic fibers per se, as well as improved blends of synthetically produced fibers with natural fibers, i.e., cellulose fibers or keratinous fibers. Results of this research have been successful, and the direction of research has been directed from the synthetic polymer per se and/or blends of said polymers with other, naturally occurring, fibers, and, more specifically, to the physical characteristics and/or endurance properties of garments produced from synthetic fabrics and/or fabric produced from blends of synthetic fibers and naturally occurring fibers.
Much research has been directed to the attainment of a garment having improved soil-release properties. Many of the synthetically produced fibers that are presently being incorporated into blends with naturally occurring fibers have a propensity to accept and retain oily grime and dirt. Accordingly, when the garment is being worn the soil and/or oily materials accumulate on the garment and settle on the fabric. Once the garment becomes soiled, it is then subjected to a cleaning process for removal of the dirt and/or oily deposits, and only a dry cleaning process will successfully clean the garment.
The cleaning process normally employed, however, is washing in a conventional home washing machine. During a wash cycle, it is virtually impossible to remove all of the soil and/or oily stains from the garment, and secondly, assuming that the undesirable materials are removed from the garment or a fairly clean garment is being washed, soil remaining in the wash water is redeposited onto the garment prior to the end of the wash cycle. Hence, when the garment is removed from the washing machine and subsequently dried, it has not been properly cleaned. Such a condition, heretofore unavoidable, is quite disadvantageous in that the garment after being worn never again assumes a truly clean appearance, but instead tends to gray and/or yellow due to the soil and/or oily materials deposited and remaining thereon. Further use and washing of the garment increases the intensity of the graying to the point that ultimately the garment is unacceptable for further wear due to its discoloration.
The composition of the present invention ameliorates the softening problem as well as the soiling problem as hereinafter described.
The problem heretofore confronted with fabrics having synthetic fibers incorporated therein, or made entirely of synthetic fibers, has been that the synthetic fibers, as well as being hydrophobic, are oleophilic. Therefore, while the oleophilic characteristics of the fiber permit oil and grime to be readily embedded therein, the hydrophobic properties of the fiber prevent water from entering the fiber to remove contaminants therefrom.
Attempts have been made to reduce the oleophilic characteristics of these synthetic fibers by coating the fibers with a coating that is oleophobic, i.e., will hinder the attachment of soil or oily materials to the fibers. Many polymer systems have been proposed which are capable of forming a film around the fibers that constitute the textile material, particularly acid emulsion polymers prepared from organic acids having reactive points of unsaturation. These treating polymers are known as soil-release agents.
The term "soil release" in accordance with the present invention refers to the ability of the fabric to be washed or otherwise treated to remove soil and/or oily materials that have come into contact with the fabric. The present invention does not wholly prevent the attachment of soil or oily materials to the fabric, but hinders such attachment and renders the heretofore uncleanable fabric now susceptible to a successful cleaning operation. While the theory of operation is still somewhat of a mystery, soiled, treated fabric when immersed in detergent-containing wash water experiences an agglomeration of oil at the surface. These globules of oil are then removed from the fabric and rise to the surface of the wash water. This phenomenon takes place in the home washer during continued agitation, but the same effect has been observed even under static conditions. In other words, a strip of polyester/cotton fabric treated with a dilute solution of the composition of the present invention and soiled with crude oil, when simply immersed in a detergent solution will lose the oil even without agitation.
Concentrated solutions of soil-release agents have been padded onto fabrics by textile manufacturers to impart a permanent soil-release finish to the fabric. As the amount of soil-release agent on the fabric is increased, the capability of the fabric to release soil is increased. However, fabrics with this permanent soil-release finish possess many disadvantages. As the amount of soil-release agent on the fabric is increased, the fabric has a tendency to become stiffer and lose the desirable hand characteristic of the fabric. Fabrics with a heavy application of soil-release agent do not have the same desirable appearance and hand as the same fabrics without the soil-release coating. Furthermore, practically speaking, there is a set range of soil-release agent that can be applied, dictated by commercial success.